electromagnets

Question 1

how do magnets work

Answer 1

A magnet has a north and a south pole and generates it’s own magnetic field.

Question 2

what is a magnetic material

Answer 2

Magnetic
material
A material that is attracted to a magnet, such as, iron, steel, nickel or cobalt.

Question 3

what is a magnetic field

Answer 3

Magnetic field

A region of space in which there is a magnetic force felt by a magnet or magnetic material.

Question 4

what is a magnetic field line

Answer 4

Magnetic field
lines
Imaginary lines that show the direction of the force on a magnetic material.

Question 5

what is a permanent magnet

Answer 5

Permanent
magnet
An object which always has its own magnetic field. I cannot be switched on or off.

Question 6

what is an electromagnet

Answer 6

Electromagnet
A temporary magnet produced using an electric field.
Magnetise
Turn object into a magnet.

Question 7

what are the laws of attraction in poles

Answer 7

Magnetic poles either attract or repel one another:
• North poles repel north poles.
• South poles repel south poles.
• North poles attract south poles.

Question 8

what are the three magnetic elements

Answer 8

Iron, cobalt and nickel are the only elements which are magnetic materials (they are attracted to a magnet). Steel is also a magnetic material because it contains iron.

Question 9

what formation do stronger magnetic field lines take

Answer 9

Magnetic field lines are used to represent a magnetic field.
The magnetic filed is strongest where the field lines are close together.
The shape of a magnetic field can be
determined using a plotting compass or iron filings.

Question 10

how do you make an electromagnet stronger

Answer 10

An electromagnet can be made stronger by:
• Increasing the number of loops in the coil.
• Increasing the current flowing through the coil.
• Using a magnetic material as the core of the electromagnet.

Question 11

what are the differences between permanent magnets and electromagnets

Answer 11

Key differences between permanent magnets and electromagnets:
• Electromagnets can be switched off.
• Electromagnets can be made much stronger than permanent magnets.

Question 12

what are uses for electromagnets

Answer 12

Uses of electromagnets:
• Moving large objects such as pieces of iron or steel in a factory or cars in a scrap yard. • Electric motors.
• High speed levitating trains.

Question 13

why do navigation compasses work

Answer 13

The Earth has a magnetic field and behaves as though there is a giant bar magnet inside it. This is why a compass can be used for navigation.